right there with the wright brothers' plane, lindberg's plane, the "spirit of saint louis," and the apollo 11 space capsule. bertrand hopes "solar impulse" will eventually have a home here as well, and he told us the inspiration for the airplane started with that balloon landing in the desert. >> piccard: when i landed there, there were 40 kilos, 80 pounds, of liquid propane out of the 3.7 tons from the take-off. it was almost a failure due to the dependency on fuel, and on that day, i made a promise-- i made a promise that, the next time i would fly around the world, it would be with no fuel at all. >> simon: earlier this year, they made their longest flights yet, from switzerland to spain, and then across the mediterranean to morocco and back. for the flight around the world, they will be in the air 20 days and 20 nights... >> bonjour, le maroc! ( cheers and applause ) >> simon: ...with several stops so the pilots can take turns. flying over the swiss alps is pleasant enough, but think about it-- i can't move, i can't stand up. and if you want to think about a really pleasant thought, th